error: this item has comments with 4 forward slashes (`////`). These look like doc comments, but they aren't
  --> $DIR/four_forward_slashes_first_line.rs:1:1
   |
LL | / //// borked doc comment on the first line. doesn't combust!
LL | | fn a() {}
   | |_
   |
   = note: `-D clippy::four-forward-slashes` implied by `-D warnings`
   = help: to override `-D warnings` add `#[allow(clippy::four_forward_slashes)]`
help: make this a doc comment by removing one `/`
   |
LL + /// borked doc comment on the first line. doesn't combust!
   |

error: aborting due to previous error